Outcome and prognosis of isolated carotid vasculitis.

OBJECTIVE: To assess the prognosis and outcome of patients with isolated carotid vasculitis. METHODS: We performed a retrospective multicenter study of 36 patients (median age at diagnosis was 37 [IQR 27-45] years and 11 [31 %] patients were men) with initial presentation as isolated carotid vasculitis. Study endpoints included vascular complications, relapses, and progression to large vessel vasculitis (i.e. Giant cell arteritis or Takayasu). RESULTS: The most frequent involvement was the left internal carotid artery (39 %), and 81 % had stenosis. After a median follow-up of 32 months [IQR 12-96], 21 (58 %) patients had a vascular event, including 31 % of new onset vascular lesions and 25 % of stroke/transient ischemic attack. Patients with stroke had less carotidynia at diagnosis (33 % vs 74 %, p = 0.046), higher significant carotid stenosis (i.e. > 50 %) (89 % vs. 30 %, p = 0.026) and higher severe carotid stenosis (i.e. >70 %) (67 % vs 19 %, p = 0.012), compared to those without stroke. Twenty (52 %) patients experienced relapses. High CRP at diagnosis was associated with relapses (p = 0.022). At the end of follow-up, 21 (58 %) patients were classified as having Takayasu arteritis, 13 (36 %) as isolated carotid vasculitis, and two (6 %) as giant cell arteritis. CONCLUSION: Carotid vasculitis may occur as a topographically limited lesion and is associated with significant rate of vascular complications.

Pregnancy outcome in patients with a medical history of immunoglobulin A vasculitis: a case-control study.

OBJECTIVE: Data on obstetric outcomes in patients with a history of immunoglobulin A vasculitis (IgA-V) are lacking. The aim of this study was to assess maternal, neonatal, and vasculitis outcomes during pregnancy. METHOD: We conducted a French retrospective case-control study. Pregnancies of patients with a history of IgA-V (cases) were retrospectively studied and compared to pregnancies in women who developed IgA-V after their pregnancies and to pregnancies in healthy women (controls). RESULTS: Twenty-six pregnancies in patients with a history of IgA-V were included and compared to 15 pregnancies in women who later developed IgA-V and 52 pregnancies in healthy women. Both gestational hypertension and pre-eclampsia were more frequent in the case group than in the other groups (23% vs 0% vs 0%, p < 0.01; 12% vs 7% vs 0%, p = 0.04). Hypertensive disorder of pregnancy occurred more frequently in patients with pre-existing kidney disease (78% vs 12%, p < 0.01). Caesarean section was more often performed in the case group than in the other groups (27% vs 0% vs 10%, p = 0.04). No foetal loss or maternal deaths occurred. There were no differences in delivery term or birth weight. No vasculitis flares were observed during pregnancy. CONCLUSION: Women with a history of IgA-V appear to be at higher risk for gestational hypertension and pre-eclampsia, especially in cases with renal involvement; however, both mother and newborn outcomes appear to be favourable.

L'haploinsuffisance de A20 : que doit connaître le clinicien?

A20 Haploinsufficiency (HA20) is a monogenic autoinflammatory disease associated with an autosomal dominant mutation in the TNFAIP3 gene. It induces a defect in the inactivation of the pro-inflammatory NF-κB pathway. Less than 200 cases have been described worldwide. The clinical picture of the disease is essentially based on the association of recurrent fever and/or biologic inflammatory syndrome, aphtosis, often bipolar, and cutaneous folliculitis. However, the clinical spectrum of HA20 is very broad, including gastrointestinal (mainly colonic ulceration), articular, cutaneous, pericardial and lymph node involvement, as well as frequent association with organ-specific or non-specific autoimmune manifestations and/or autoantibodies, including antinuclear antibodies and anti-dsDNA. As a result, the diagnosis of a number of systemic or organic disorders, most notably Behçet's disease, Crohn's disease, and sometimes even systemic lupus, has been corrected to HA20 by molecular research for a heterozygous mutation with functional deficiency of TNFAIP3. Although the first signs of the disease often appear in the first years of life, the diagnosis is often made in adulthood and requires the involvement of both paediatric and adult physicians. Treatment for HA20 is not codified and relies on conventional or biological immunomodulators and immunosuppressants adapted to the patient's symptomatology. This review highlights the enormous diagnostic challenges in this autoinflammatory disease.

Early infectious risk in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis according to remission-induction therapy.

OBJECTIVE: Few comparative data exist on early infections secondary to remission-induction therapy (RIT) with rituximab (RTX) versus cyclophosphamide (CYC) in newly diagnosed anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients. We compared and analysed the rates and predictors of severe infection in such patients within the first 6 months following RIT. METHOD: From the Caen University Hospital databases, we included all consecutive adults newly diagnosed with ANCA-positive granulomatosis with polyangiitis or microscopic polyangiitis between January 2006 and December 2019. We compared rates of survival without severe infection and survival without infections of any severity within 6 months of RIT and used a multivariate Cox analysis to identify predictors of infection. RESULTS: We included 145 patients, 27 in the RTX and 118 in the CYC group. Patients in the RTX group more frequently had pneumococcal vaccination (p < 0.01) and creatinine < 150 µmol/L; other characteristics were comparable between the two groups. Overall, 37 severe infections and 65 infections of any severity were recorded. Rates of survival without severe infection were similar in both groups (p = 0.69), but survival without infections of any severity was lower in the RTX group (p = 0.005). In multivariate analysis, risk factors at diagnosis for severe infections included chronic urinary tract disease, dialysis, and absence of trimethoprim-sulfamethoxazole prophylaxis (p < 0.01 each). CONCLUSIONS: Within 6 months of RIT, rates of survival without severe infection were similar in newly diagnosed ANCA-positive AAV patients treated with RTX or CYC, but survival rates without infections of any severity appeared to be lower with RTX treatment.

Efficacy, tolerance and acceptability of pulsed dye laser on facial and neckline telangiectasias in systemic scleroderma: a prospective open-label monocentric study in 21 patients.

Facial and neckline telangiectasias have an underestimated yet important impact on quality of life of patients with systemic scleroderma (SSc). This monocentric, prospective, open-label, intra-patient comparative study was conducted in 21 consecutive patients with SSc. Patients underwent 4 sessions of PDL 8 weeks apart. A final quadruple assessment was performed by several raters 2 months after the last session, based on the following criteria: change in telangiectasia number; subjective improvement score (LINKERT scale); impact on the quality of life (QoL; SKINDEX score); visual analog pain scale; adverse effects (AEs), including treatment discontinuation for PDL-induced purpura and patient satisfaction. The mean telangiectasia number decreased by 5 (32%) at the end of the protocol. Eighteen patients (85.7%) reported an improvement or a strong improvement, versus 73.81% for the expert committee. Immediate session pain (mean = 3.4/10) was slightly less than overall pain (mean = 4.6/10). Ten patients (47%) experienced at least one AE (oozing/crusts, edema, epidermal blistering), including PDL-induced purpura in 3 patients (14%). AEs were mostly transient (<1 week) and mild (CTCAE grade 1). All QoL parameters improved after treatment, and 85% of patients were satisfied.

Diagnostic and therapeutic approach to adult central nervous system vasculitis.

The clinical manifestations of central nervous system (CNS) vasculitis are highly variable. In the absence of a positive CNS biopsy, CNS vasculitis is particularly suspected when markers of both vascular disease and inflammation are present. To facilitate the clinical and therapeutic approach to this rare condition, CNS vasculitis can be classified according to the size of the involved vessels. Vascular imaging is used to identify medium vessel disease. Small vessel disease can only be diagnosed with a CNS biopsy. Medium vessel vasculitis usually presents with focal neurological signs, while small vessel vasculitis more often leads to cognitive deficits, altered level of consciousness and seizures. Markers of CNS inflammation include cerebrospinal fluid pleocytosis or elevated protein levels, and vessel wall, parenchymal or leptomeningeal enhancement. The broad range of differential diagnoses of CNS vasculitis can be narrowed based on the disease subtype. Common mimickers of medium vessel vasculitis include intracranial atherosclerosis and reversible cerebral vasoconstriction syndrome. The diagnostic workup aims to answer two questions: is the neurological presentation secondary to a vasculitic process, and if so, is the vasculitis primary (i.e., primary angiitis of the CNS) or secondary (e.g., to a systemic vasculitis, connective tissue disorder, infection, malignancy or drug use)? In primary angiitis of the CNS, glucocorticoids and cyclophosphamide are most often used for induction therapy, but rituximab may be an alternative. Based on the available evidence, all patients should receive maintenance immunosuppression. A multidisciplinary approach is necessary to ensure an accurate and timely diagnosis and to improve outcomes for patients with this potentially devastating condition.

Characterizing hospital pathways for the care of acquired hemophilia in France using comprehensive national health data.

PURPOSE: Acquired hemophilia (AH) is a rare, serious bleeding disorder most often associated with older age and life-threatening complications. The patient care pathway for AH is complex because of the different types of bleeding, the presence of comorbidities, and the heterogeneity of medical specialists who care for these patients. METHODS: This observational study used the French national PMSI (Programme de médicalisation des systèmes d'information) database to characterize patients with AH in real-life practice and analyze their hospital pathway. In total, 180 patients with AH were identified over a 5-year study period (January 2010 to December 2014), based on three criteria: bypassing agent use, International Classification of Diseases, 10th revision code allocation, and aged over 65 years. Comparison of the incidence rate of AH versus registry data validated the PMSI as an epidemiological database. RESULTS: Rituximab was prescribed more often (60/180; 33.3%) than expected following guidelines and was associated in half of cases to early infections (32/60; 53.3%), surgery procedures were frequently performed during the year before AH onset (29/159; 18.2%), which may suggest a triggering effect, extended hospital stays (median: 20 days) and mortality remaining high (66/180; 36.7%) that occurred mainly during the first month after AH diagnosis. Median costs and number of injections were comparable between recombinant activated factor VII and plasma-derived activated prothrombin complex concentrate. CONCLUSION: These findings could inform future medico-economic approaches in this AH population (duration of stays, bypassing agents, rituximab use, comorbidities, hospitalizations with infections).

Further characterization of clinical and laboratory features in VEXAS syndrome: large-scale analysis of a multicentre case series of 116 French patients.

BACKGROUND: A new autoinflammatory syndrome related to somatic mutations of UBA1 was recently described and called VEXAS syndrome ('Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic syndrome'). OBJECTIVES: To describe clinical characteristics, laboratory findings and outcomes of VEXAS syndrome. METHODS: One hundred and sixteen patients with VEXAS syndrome were referred to a French multicentre registry between November 2020 and May 2021. The frequency and median of parameters and vital status, from diagnosis to the end of the follow-up, were recorded. RESULTS: The main clinical features of VEXAS syndrome were found to be skin lesions (83%), noninfectious fever (64%), weight loss (62%), lung involvement (50%), ocular symptoms (39%), relapsing chondritis (36%), venous thrombosis (35%), lymph nodes (34%) and arthralgia (27%). Haematological disease was present in 58 cases (50%): myelodysplastic syndrome (MDS; n = 58) and monoclonal gammopathy of unknown significance (n = 12; all patients with MGUS also have a MDS). UBA1 mutations included p.M41T (45%), p.M41V (30%), p.M41L (18%) and splice mutations (7%). After a median follow-up of 3 years, 18 patients died (15·5%; nine of infection and three due to MDS progression). Unsupervised analysis identified three clusters: cluster 1 (47%; mild-to-moderate disease); cluster 2 (16%; underlying MDS and higher mortality rates); and cluster 3 (37%; constitutional manifestations, higher C-reactive protein levels and less frequent chondritis). The 5-year probability of survival was 84·2% in cluster 1, 50·5% in cluster 2 and 89·6% in cluster 3. The UBA1 p.Met41Leu mutation was associated with a better prognosis. CONCLUSIONS: VEXAS syndrome has a large spectrum of organ manifestations and shows different clinical and prognostic profiles. It also raises a potential impact of the identified UBA1 mutation.

Renal and overall outcomes of double-positive (ANCA and anti-GBM antibodies) patients compared to ANCA-associated vasculitis patients with severe renal involvement: A multicenter retrospective study with systematic renal pathology analysis.

OBJECTIVE: Double-positive patients (DPPs), combining serum and/or histological findings for glomerular basement membrane (GBM) disease and anti-neutrophil cytoplasmic antibodies (ANCAs), are rare and poorly described. This study aimed to compare characteristics between DPPs and ANCA-associated vasculitis (AAV) patients with severe renal involvement. METHOD: This retrospective multicentre study compared 33 DPPs and 45 AAV patients with severe renal involvement (serum creatinine > 300 µmol/L), all with biopsy-proven nephropathy. RESULTS: All DPPs (including 18% exhibiting negative serum anti-GBM antibodies) presented severe acute kidney failure with histological GBM involvement. Compared to AAV patients, they had higher serum creatinine (719 vs 501 µmol/L; p = 0.006) and a higher proportion of patients requiring initial renal replacement therapy (82% vs 36%; p < 0.001). Berden classification differed significantly (p = 0.003), with more crescentic glomerulonephritis and fewer sclerotic lesions in DPPs. One-year renal survival was significantly lower in DPPs than in AAV patients (27% vs 64%; p < 0.0002). With comparable proportions of ANCA subtypes (two-thirds with anti-myeloperoxidase autoantibodies), numbers of extrarenal manifestations (mostly pulmonary in two-thirds), remission-inducing immunosuppressants, and median follow-ups (3 years) between groups, relapse rates were similar: 9.1% of DPPs and 10% of AAV patients. CONCLUSION: Although DPPs have features of both kinds of vasculitis, the anti-GBM component is the dominant phenotype, with more severe renal presentation and prognosis compared to AAV patients with severe renal failure. Simultaneous testing of both antibodies and systematically performed renal biopsy should be recommended in all rapidly progressing glomerulonephritis patients to recognize this difficult-to-treat, rare disease.

[Spontaneous intracranial hypotension: A rare cause of headache in systemic lupus erythematosus]. / Hypotension intracrânienne : une cause rare de céphalées au cours du lupus systémique.

INTRODUCTION: Spontaneous intracranial hypotension (SIH), a rare cause of headache, may be idiopathic or secondary, in particular to Systemic Lupus Erythematosus (SLE) where it remains exceptionally evoked or documented. CASE REPORT: A 36-year-old woman presented with postural headache, recurrent nausea and vomiting. The discovery of a nephrotic syndrome led to the diagnosis of SLE with lupus nephropathy (class IV-G-(A)). A brain MRI showed signs of intracranial hypotension with tonsil ptosis and a left parietal hypersignal, and leading to a diagnosis of neurolupus with SIH. Treatment with prednisone, cyclophosphamide, and then mycophenolate mofetil allowed a rapid complete response of all systemic, renal and neurological manifestations, including the iconographic signs of intracranial hypotension. CONCLUSION: Headaches are frequent and often unexplained during SLE. Their orthostatic character should, if appropriate, suggests a SIH and lead to perform a brain MRI, even in the absence of other neurological signs.

[Lung involvement of pyoderma gangrenosum: Diagnostic and therapeutic discussion based on a case report and a targeted literature review]. / Atteinte pulmonaire de pyoderma gangrenosum : discussion diagnostique et thérapeutique à partir d'un cas et d'une revue ciblée de la littérature.

INTRODUCTION: Pyoderma gangrenosum (PG) is a rare, mainly dermatological condition, whose unusual and little-known lung involvement presents a diagnostic and therapeutic challenge. CASE REPORT: A 66-year-old man, followed for 6 years for an IgA monoclonal gammopathy of undetermined significance and an initially cutaneous corticosteroid-dependent PG, received a pneumonectomy for a mass suspected of neoplasia, that turns out to be a PG pulmonary localisation. During successive pneumopathies, sometimes dyspneic and excavated, several hypotheses are discussed. Various infectious and immunological explorations, and various antibacterial/fungal or immunosuppressive therapies are conducted, to finally conclude to pulmonary and/or cutaneous recurrences of PG. The outcome at 14 months seems finally favourable with tofacitinib. CONCLUSION: The recognition of cutaneous involvement of PG, which is essential for the diagnosis of its lung involvement, is probably the mirror of its evolution under treatment. Only multidisciplinary confrontation of reported cases will allow the elaboration of diagnostic and therapeutic recommendations.

IVIg increases interleukin-11 levels, which in turn contribute to increased platelets, VWF and FVIII in mice and humans.

The mechanisms of action of intravenous immunoglobulins (IVIg) in autoimmune diseases are not fully understood. The fixed duration of efficacy and noncumulative effects of IVIg in immune thrombocytopenia (ITP) and acquired von Willebrand disease (AVWD) suggest other mechanisms besides immunological ones. Additionally to the peripheral destruction of platelets in ITP, their medullary hypoproduction emerged as a new paradigm with rescue of thrombopoietin receptor agonists (TPO-RA). In an ITP mouse model, interleukin (IL)-11 blood levels increase following IVIg. IL-11 stimulates the production of platelets and other haemostasis factors; recombinant IL-11 (rIL-11) is thus used as a growth factor in post-chemotherapy thrombocytopenia. We therefore hypothesized that IVIg induces IL-11 over-production, which increases platelets, VWF and factor VIII (FVIII) levels in humans and mice. First, in an ITP mouse model, we show that IVIg or rIL-11 induces a rapid increase (72 h) in platelets, FVIII and VWF levels, whereas anti-IL-11 antibody greatly decreased this effect. Secondly, we quantify for the first time in patients with ITP, AVWD, inflammatory myopathies or Guillain-Barré syndrome the dramatic IL-11 increase following IVIg, regardless of the disease. As observed in mice, platelets, VWF and FVIII levels increased following IVIg. The late evolution (4 weeks) of post-IVIg IL-11 levels overlapped with those of VWF and platelets. These data may explain thrombotic events following IVIg and open perspectives to monitor post-IVIg IL-11/thrombopoietin ratios, and to assess rIL-11 use with or without TPO-RA as megakaryopoiesis co-stimulating factors to overcome the relative hypoproduction of platelets or VWF in corresponding autoimmune diseases, besides immunosuppressant.

[Polymyalgia rheumatic and chronic myelomonocytic leukemia]. / Pseudo-polyarthrite rhizomélique satellite d'une leucémie myélomonocytaire chronique.

INTRODUCTION: Myelodysplasia (MDS) can occur as systemic manifestations such as connective tissue diseases or vasculitis. Rheumatological manifestations are also described in such context. Herein, we report the observation of a patient with chronic myelomonocytic leukemia (CMML) who developed systemic manifestations: polymyalgia rheumatica and pericarditis. CASE REPORT: A 78-year-old patient was referred for the exploration of two months history of inflammatory shoulder pain associated with biological inflammatory syndrome. He presented with asthenia, anorexia and loss of 5kg in one month. He had a three years follow-up for a CMML without any specific treatment. All of the explorations carried out showed a typical polymyalgia rheumatica. A pericardial effusion requiring emergency drainage was synchronously diagnosed. All the symptoms occurred during a worsening of his hematological disease. The rheumatological manifestation was favorable after a short corticosteroid therapy and pericarditis did not recur after 2 years of follow-up. CONCLUSION: It should be necessary to screen patients for MDS in a context of systemic manifestation, especially in elderly patients with an abnormal blood count (cytopenia, macrocytosis and monocytosis).

[Periodic fever syndrome associated with mutations in the TNF type 1 receptor gene: A differential diagnosis of familial Mediterranean fever that should not be overlooked in patients of Mediterranean origin]. / Le syndrome de fièvre prolongée associée aux mutations du gène du récepteur au TNF de type 1 : un diagnostic différentiel de la fièvre méditerranéenne familiale à ne pas méconnaître chez les patients d'origine méditerranéenne.

INTRODUCTION: Tumor Necrosis Factor Type 1 Receptor Associated Periodic Syndrome (TRAPS) is a rare autosomal dominant autosomal autoinflammatory disease associated with mutations in the TNF type 1 receptor gene (TNFRSF1A). It is characterized by relatively long recurrent febrile seizures with an average duration of 7 days accompanied by arthralgia, myalgia, and usually a rash. In a patient of Mediterranean origin with recurrent fever, familial Mediterranean fever is the first diagnosis to be suspected by argument of frequency. METHODS: A retrospective observational study was conducted on patients from Mediterranean origin followed for TRAPS and included in the "Juvenile Inflammatory Rheumatism" (JIR) observational cohort in the national French autoinflammatory center. The age of onset of symptoms, age of diagnosis, number of years of wandering and treatments received were collected for each index case. RESULTS: Nine patients from 6 families of Mediterranean origin were included. A molecular diagnosis confirmed TRAPS in all patients. The median age at diagnosis was 26 years, the mean number of years of wandering was 17 years. The diagnosis of FMF was made first in all patients. AA amyloidosis revealed TRAPS in 2 patients. Colchicine was started without any efficacy in all cases. Five patients were treated with interleukin-1 inhibitory biotherapy with 100% efficacy. CONCLUSION: In a patient of Mediterranean origin presenting with recurrent febrile abdominal pain of AA amyloidosis, the first diagnosis to be suspected is FMF. Long relapses, dominant transmission, a non-Mediterranean relative, and the ineffectiveness of colchicine should evoke TRAPS.

Rothia spp. infective endocarditis: A systematic literature review.

OBJECTIVE: To describe the epidemiological, clinical, microbiological, and therapeutic features and outcomes of Rothia infective endocarditis (RIE) and extracardiac infections (ECRI). METHODS: We performed a systematic literature review of published cases of RIE and ECRI. RESULTS: After inclusion of a personal case report, 51 cases of RIE and 215 cases of ECRI were reported. Compared with ECRI patients, RIE patients were significantly more often males (80% versus 59%), intravenous drug users (IVDU) (20% versus 3%), immunocompetent (76% versus 31%), and infected with R. dentocariosa (55% versus 13%) but lacked significant differences with regard to median age (45 years [6-79]), rate of orodental abnormalities (33%), and six-month mortality (14%). Following microbiological documentation, RIE was most often treated with a beta-lactam antibiotic alone (39%) for a median duration of six weeks and required surgery in 39% of cases. CONCLUSION: RIE is rare and likely secondary to a dental portal of entry or cutaneous inoculation in IVDU. Its prognosis seems to be favorable.

[IgA vasculitis secondary to Klebsiella pneumoniae infection]. / Vascularite à IgA satellite d'une pneumopathie abcédée à Klebsiella pneumoniae.

INTRODUCTION: IgA vasculitis is a leucocytoclastic vasculitis of small vessels with immune deposits of IgA. It tends to occur in a post-infectious context, though the pathogenic agent is rarely found. OBSERVATION: We report, for the first time, the case of an 81-year old patient who presented with an acute IgA vasculitis with cutaneous and joint involvement during a Klebsiella pneumoniae respiratory infection. Remission of vasculitis was observed after antibiotic therapy alone. CONCLUSION: This observation reminds us of the need to search carefully for any pathogenic agent that may be driving IgA vasculitis as this may be important both for understanding aetiology and for treatment.

[ANCA and anti-MBG double-positive vasculitis: An update on the clinical and therapeutic specificities and comparison with the two eponymous vasculitis]. / Vascularites double-positives ANCA et anti-MBG : mise au point sur les spécificités cliniques et thérapeutiques et comparaison aux deux vascularites éponymes.

Double-positive vasculitis with anti-polynuclear cytoplasm (ANCA) and anti-glomerular basement membrane (GBM) antibodies is a rare entity of systemic vasculitis defined by the presence of ANCA and anti-GBM antibodies. The gradual accumulation of clinical and therapeutic data shows the usefulness of identifying and differentiating this entity from the two vasculitis respectively associated with the isolated presence of each of these two antibodies. Indeed, the double-positive ANCA and anti-GBM vasculitis appears to associate the characteristics of the demography and the extra-renal and pulmonary involvement of the ANCA-associated vasculitis on the one hand, and of the histological type and severe renal prognosis of the anti-MBG vasculitis on the other hand, with the renal involvement which is the only involvement consistently observed in double-positive vasculitis. The aim of this focus is to describe the epidemiological, clinico-biological, histological and prognostic characteristics of this entity, in light of recent literature and ongoing therapeutic changes in the two eponymous vasculitis.

[Encapsulant peritonitis]. / Une péritonite encapsulante.

INTRODUCTION: Encapsulating peritonitis is a rare but severe chronic fibrotic condition related to the development of a white fibrous membrane surrounding the digestive tract. Idiopathic forms have been described, however the disease is most often secondary to peritoneal dialysis or more rarely to surgery. Treatment is difficult and not codified. CASE REPORT: We report here the observation of a 36-year-old patient whose diagnosis of encapsulating peritonitis was made after a long sub-occlusive history, eight years after a gastric ulcer perforation. DISCUSSION: We discuss the possible etiologies and we present a focus on this rare and little-known entity.